When computers were originally invented, it was thought that they would be used for computing mathematical functions, only.
Hence, the name "computers".
Computers now cover, broadly, at least several areas:
Methods for computing mathematical functions might not be the best choice for use in the other fields, e.g. machine control.
For example, StateCharts are useful for (asynchronous) machine control, but not as useful for computing (sequential) mathematics.
 I include CRM (Customer Relationship Management) in this category.
 I include new-breed AI in this category
 e.g. Functional Programming